console: newport_con: fix an issue about leak related system resources

A call of the function do_take_over_console() can fail here.
The corresponding system resources were not released then.
Thus add a call of iounmap() and release_mem_region()
together with the check of a failure predicate. and also
add release_mem_region() on device removal.

Fixes: e86bb8ac ("[PATCH] VT binding: Make newport_con support binding")
Suggested-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200423164251.3349-1-zhengdejin5@gmail.com

drivers/video/console/newport_con.c

@@ -32,6 +32,8 @@
 #include <linux/linux_logo.h>
 #include <linux/font.h>
 
+#define NEWPORT_LEN	0x10000
+
 #define FONT_DATA ((unsigned char *)font_vga_8x16.data)
 
 /* borrowed from fbcon.c */
@@ -43,6 +45,7 @@
 static unsigned char *font_data[MAX_NR_CONSOLES];
 
 static struct newport_regs *npregs;
+static unsigned long newport_addr;
 
 static int logo_active;
 static int topscan;
@@ -702,7 +705,6 @@ const struct consw newport_con = {
 static int newport_probe(struct gio_device *dev,
 			 const struct gio_device_id *id)
 {
-	unsigned long newport_addr;
 	int err;
 
 	if (!dev->resource.start)
@@ -712,7 +714,7 @@ static int newport_probe(struct gio_device *dev,
 		return -EBUSY; /* we only support one Newport as console */
 
 	newport_addr = dev->resource.start + 0xF0000;
-	if (!request_mem_region(newport_addr, 0x10000, "Newport"))
+	if (!request_mem_region(newport_addr, NEWPORT_LEN, "Newport"))
 		return -ENODEV;
 
 	npregs = (struct newport_regs *)/* ioremap cannot fail */
@@ -720,6 +722,11 @@ static int newport_probe(struct gio_device *dev,
 	console_lock();
 	err = do_take_over_console(&newport_con, 0, MAX_NR_CONSOLES - 1, 1);
 	console_unlock();
+
+	if (err) {
+		iounmap((void *)npregs);
+		release_mem_region(newport_addr, NEWPORT_LEN);
+	}
 	return err;
 }
 
@@ -727,6 +734,7 @@ static void newport_remove(struct gio_device *dev)
 {
 	give_up_console(&newport_con);
 	iounmap((void *)npregs);
+	release_mem_region(newport_addr, NEWPORT_LEN);
 }
 
 static struct gio_device_id newport_ids[] = {